The present invention relates to the manufacture of sliding clasp fasteners, and in particular to the production of sealed end stringers for sliding clasp fasteners from a pair of stringer tapes each provided on one edge thereof with a row of fastening elements.
In a conventional sliding clasp fastener, the stringers comprise two flexible tapes respectively provided with two rows of interengageable fastening elements, which may, for example, be formed from appropriately shaped continuous filaments of plastics material, the filaments being sewn to the tapes. The fastener is operated in a known manner by a slider movable along the rows of fastening elements between stop means at either end of the fastener.
In the case of a fastener which in use must permit the two stringers to be completely separated, one of the stringers, to which the slider is permanently attached, is provided at one end with an open end box member, and the other stringer is provided with a guide member insertable through alignable slots in the slider and box member to effect an initial connection of the stringers.
The provision of the stop means and guide member, and the securing of the tape ends against fraying, may entail different manufacturing procedures and materials, which increases the cost of the finished fastener.
The invention therefore has as one of its objects the provision of a method for producing finished stringers for sliding clasp fasteners in a series of steps of a single manufacturing process, without recourse to distinctly different processes and materials.
A further object of the invention is to provide a method as mentioned above in which the steps are carried out in relation to continuous tape lengths for a plurality of fasteners, rather than in relation to tape lengths for individual fasteners, so as to correspondingly simplify handling of materials and manufacturing operations.
A further object of the invention is to provide a method of the kind described in which plastics materials may be utilized both to seal the ends of the stringers and to furnish the requisite end fittings.